Clefairy

Clefairy's main niche lies in its stellar ability, Magic Guard, granting it an immunity to all forms of passive damage, making it stand out among other defensive Pokemon. Additionally, Clefairy sports great special bulk bolstered by Eviolite, which lets it soft check some of NU's most powerful special attackers such as Magmortar, Pyroar, and mixed attacking Samurott. Though Clefairy does face stiff competition from Mega Audino, which sports better bulk and is immune to Knock Off's item-removal effect, Clefairy sets itself apart with its ability to only take one to turn to restore lost HP and only use up one moveslot in doing so, letting it use a wider array of support options. However, Clefairy relies on Eviolite in order to stomach hits from powerful attackers, making it vulnerable to Knock Off and therefore unable to switch into Dark- and Fighting-types as well as it would like to despite its resistances. Clefairy also suffers from being passive, as even with Calm Mind boosts its damage output is still disappointing, causing it to be a free switch in for quite a few Pokemon such as Steelix and Rhydon.